Image control tube and method of printing



Nov. 20, 1956 J, F, MacGRlFF IMAGE CONTROL TUBE AND METHOD OF PRINTINGFiled Feb. 14, 1952 IN V EN TOR.

ATTomYEK United States Patent INIAGE CONTROL TUBE AND METHOD OF PRINTINGJack E. MacGrilf, Detroit, Mich. Application February 14, 1952, SerialNo. 271,579 7 Claims. (Cl. 346-74) This invention relates to an imagecontrol tube, and more particularly to a cathode ray tube together withmechanism for utilizing said tube for transmitting an image upon amoving web.

It is the object of the present invention to provide a novel imagecontrol cathode ray tube.

It is the further object of this invention to provide a novel cathoderay tube adapted for transmitting and effecting the application of animage to a moving web permanently thereon.

It is the further object of this invention to provide a novel cathoderay tube with conductors in the end face thereof for transmittingelectron rays from the tube to an electrode spaced therefrom.

It is the further object of this invention to provide a mechanism forutilizing said transmitted electron rays for depositing a permanentimage upon a moving web of image receiving material spaced intermediatesaid conductors and said electrode.

It is the further object of this invention to provide a novel method andapparatus of image printing upon a moving web.

These and other objects will be seen from the following specificationand claims in conjunction with the appended drawing in which:

Fig. 1 is a diagrammatic partially sectioned elevational view of thepresent image control tube as used for printing upon a moving web.

Fig. 2 is a perspective view of the image control tube.

Fig. 3 is an enlarged perspective view of the high voltage electrodeused in conjunction with said tube.

Fig. 4 is a diagrammatic illustration of a simple mechanical scanner forproducing a video image signal from a permanent image upon a rotatabledrum.

Fig. 5 is a fragmentary plan view of a portion of the illustration ofFig. 4 showing the relation between the light shield, the revolving discand the screen employed in said mechanical scanner device; and

Fig. 6 is a perspective view illustrating the relation between theshield, the disc and the screen.

It will be understood that the above drawing diagrammaticallyillustrates merely one embodiment of the invention, and that otherembodiments are contemplated within the scope of the claims hereafterset forth.

Referring to the drawing, the present image control cathode ray tubeincludes a hollow glass envelope with an enlarged portion 11 terminatingat its smallest diameter in the elongated cylindrical shank 12 which isclosed at its end as shown in Fig. 1. The enlarged portion 11 terminatesin the end face 13 which is arranged substantially at right angles tothe longitudinal axis of the tube shank and is relatively thickened withrespect to the other portions of the tube. The end face 13 isconstructed without a fluorescent screen as commonly used, and insteadhas formed or molded within said end face a plurality of elongatedparallel spaced conductors 14, which are arranged in a row AB acrosssaid end face as shown in Fig. 2.

Said conductors are sealed within end face 13 so that theircorresponding ends terminate at or adjacent the corresponding inner andouter surfaces of end face 13.

Said conductors are arranged in parallel insulated relation to eachother and are parallel to the central longitudinal axis of the tube11-12. The interior space 15 of the tube is evacuated to a high vacuumin the conventional manner.

The present tube has centrally and axially housed therein adjacent theclosed end of the tube shank 12 a standard cathode-electron-gun assembly16 including the cathode emitting element 17 which is connected by thelead 18 to the power line 19.

Said electron gun assembly also includes the forwardly arranged axiallyaligned cylindrical control grid 20 and the two forwardly arrangedaxially aligned accelerating anodes 21 and 22. The voltages of thecontrol grid 20 and the anodes 21 and 22 are progressively increasedwith respect to each other towards the enlarged end of the tube forcontrolling the velocity of electron beam 23.

It is understood that the control grid 20 in response to image signals54 through the lead 26 regulates the quantity of electrons which make upthe electron beam 23 at any instant.

The tube or the electron beam 23 is focused by the focusing coil 24which is suitably energized in a conventional manner. There is alsoprovided a conventional deflection yoke 25 around the tube shank.12whereby the electron beam may be deflected magnetically in aconventional manner. The upper and lower coils 25 are adapted to bendthe electron beam to the right or to the left of the geometricallongitudinal axis of the tube. The other two deflection coils, one ofwhich is shown in dotted lines, arranged on diametrically opposite sidesof the tube shank, are adapted to bend the electron beam upwardly ordownwardly. In the present embodiment said latter deflection coils areemployed to maintain the electron beam in a horizontal plane whichpasses through the row of conductors AB shown in Fig. 2. It iscontemplated that the deflection of the electron beam could also beeffected electrostatically, if desired.

As it is the purpose of the presentdevice to effect merely a horizontaldeflection of the electron beam for intermittent and successive registrywith the various con doctors 14 arranged in the row AB, it is understood'that no vertical deflection of the beam is contemplated except such asmight be necessary to align the beam with the row of conductors AB,Figs. 1 and 2.

Image control lead 26 to the grid 20 is connected with the power source19 by the lead 27 shown in Fig. 1.

A moving web 28 of paper or other image receiving material is arrangedforwardly of the end face 13 of said tube and bears against drum 29which revolves at a constant speed upon its horizontal axis 30 arrangedparallel to and spaced from the row of conductors 14 in the tube endface 13. As shown in Fig. 1 the web 28 is moving upwardly from the drum29 and as it passes the row A-B of conductors 14 said Web is spacedclosely to the outside face of said tube a short distance measured inthousandths of an inch, such as .008 of an inch, for

illustration. 'It is contemplated, however, that this space is variabledepending upon the voltages employed and other factors hereafterdescribed.

The high voltage stationary electrode blade 31 has a thin electronreceiving edge 32 arranged parallel to and opposite from the row AB ofconductors 14 in the tube face 13. Said electrode is positioned upon theinside of the revolving drum and remains in the stationary positionshown in Fig. 1.

The formed housing 34 is so arranged and associated with-respect to theend face of said tube and the web .28 as to provide a passageway for asuitable pigment in the form of smoke 36 which is drawn from a smokepigment generator 34' and is forced between the conductors 14 in thetube face and the moving web of paper.

This smoke pigment may be exhausted or recirculated through the blower35 and conducted through the continuous housing element 34 which isfragmentarily shown, for illustration. A constant density of smokepigment is maintained at the space between the row of conductors 14 andthe web 28 of image receiving material.

Operation When the tube is operating, the high voltage electron beam 23is caused to scan the row of conductors 14 by the magnetic scanningfield produced by the deflection yoke 25. By varying the intensity ofthe scanning field the electron beam 23 will be so deflected as tointermittently scan the row of conductors 14 starting at point A andmoving across to point B, Fig. 2.

If the row of conductors 14 is horizontal to the base of the device as',in the present embodiment, then only the horizontal scanning field isactuated by the standard saw-tooth signal, with the electron beam movingfrom point A to point B during the slow moving horizontal signal andreturning from point B to point A during the rapid-retrace or flybacksignal in the conventional manner.

As above set forth the vertical scanning field of the defiection yoke 25is used only to position the scanning trace of the electron beam 23 onthe row A--B of conductors 14.

As shown in Fig. 1 the Web 28 is adapted to move vertically past theface of the tube. The image signal designated by the numeral 54 is fedto the control grid 20 of the electron-gun-assembly 16 by the lead wire26. The highvoltage electron beam is emitted from the cathode .17 in thequantity allowed by the instantaneous image signal on the control grid.The electron beam 23 passes through the scanning field controlled by thedeflection yoke25 and strikes one conductor 14, passes through the sameand through the face of the tube; and then passes through the smokepigment 36 and the web 28 and completes the electrical circuit to thehigh voltage electrode 31-32 inside the rotating drum 29.

As the electron beam 23 passes through the smoke pigment 36, particlesof the pigment are carried by the beam to the paper and impinge upon thepaper and into the surface of the paper or other image receivingmaterial 28 in a permanent manner.

Thesmoke pigment 36 may carry an electrostatic or electromagnetic chargeto assist in the image deposition upon the web 28, which charge isformed in a standard and conventional manner.

Thus, with the yoke 25 causing the beam 23 to sue-- cessively scanconductors 14 from one end to the other of row AB of said conductors, itis apparent that particles of the pigment will be deposited upon the webin a row corresponding to the row of conductors. Thus, as the web 28 ofpaper or other material moves, image lines will be formed across web 28in such a manner that the image formed on and in the paper by thepigment particles corresponds to the amount of electrons passed by thecontrol grid 20.

Therefore, it follows that the image on and in the web 28 is controlledby the image signal 54 to the electrongun-assembly 16.

The high voltage electrode 31 is operated at a higher potential than theaccelerating anode 22; and the latter anode is at a higher potentialthan accelerating anode 21. Furthermore, the latter anode 21 operates ata higher voltage than the cathode emitter 17. The control grid 20 isoperated at a lower potential than said cathode emitter 17. Theinstantaneous and varying potential of the grid 20 as regulated by theimage signal 54, thus controls the deposition of smoke pigment upon theweb 28 in a row corresponding to the row of spaced conductors 14.

Magnitudes of the various voltages depend upon various factors such asthe dimensions of the tube 11--12, the web thickness, the distance ofthe row of conductors from the surface of the web on the revolving drum,and the density and substance of the smoke pigment 36.

The image control tube above described may be operated from anon-interlaced television type video signal, or may be operated from thesimple mechanical scanner shown in Figs. 4, 5, and 6 for producing imagesignal 54, for illustration.

To produce the same image many times upon a web of paper, such as inprinting, a master image 37 is secured to the rotatable drum 38 having alongitudinal axis 39.

Light from a lamp 40 illuminates a strip 41 of the image parallel to theaxis 39 of the revolving image drum 38.

This strip 41 of image is focused by the lens 42, which is spacedforwardly of said drum 38, unto a suitable rectangular screen 43 whichmay be constructed of milk glass, said screen being suitably spaced fromlens 42 as diagrammatically indicated in Fig. 4.

A revolving disc 44 is driven by the motor 45 and has formed thereinadjacent its periphery a plurality of circumferentially spaced radialslots 46.

A rectangular light shield 47 with elongated longitudinal slot 48 isspaced forwardly of the revolving disc 44 as shown in Fig. 4 and in Fig.6. Thus, the revolving disc so moves its slots 46 with respect to thelight shield slot 48 as to permit only a spot 49 of the image line 41 tobe focused by the lens 42 upon the screen 43 at any instant.

Thus, a moving spot of light is produced upon the screen 43 formed bythe shielding effect of the slots 46 in the revolving disc 44 and theslot 48 of light shield 47 in the manner illustrated in Fig. 6.

A suitable lens 50 spaced from the screen 43 focuses all points 49 onthe moving line traced by the moving spot of light on to the mirror 50which in turn reflects the same on to the sensitive photocathode of aphoto multiplier tube 51. Variations in light intensity received by thephotomultiplier are transformed into variations in electrical current,which are directed by the lead 52 to the amplifier 53 and are fed asimage control signals 54 to the grid 20 of the image control tube bymeans of the lead 26 shown in Fig. 1.

The master image drum 38 is synchronized with the movement of the web28. The horizontal scanning frequency of the deflection yoke 25 issynchronized with the revolving disc slots 46 to reproduce on the movingweb 28 the image lines 41 scanned by the device on the master image drum38.

I A light beam from the lamp 55 shown in Fig. 6 is allowed to fall uponthe photo-tube 57 arranged upon the opposite side of disc 44 from lamp55, as each shutter slot 46 passes. The pulse-signal from photo-tube 57is used as a synchronizing signal for the horizontal scanning electroniccircuit for the deflection yokes 25 in the image control tube 11ll2, andlocks the scanning oscillator of said deflection yoke in step withrotating disc 44.

The speed of the scanning disc 44 is fixed as operated by motor 45 anddepends on the number of shutter slots 46 and the desired number ofimage trace lines per picture or image.

As one shutter slot 46 completes its travelpast the horizontal slot 48of light shield 47, another shutter slot 46 is just beginning to travelpast slot 48 at its opposite end. Thus, a continuous series of traceline signals are scanned from the master image drum.37'-38 and arereproduced instantaneously by the high voltage electron beam 23 passingthrough the individual conductors 14 and forcing particles of the smokepigment 36 into and upon the moving web 28, which may be paper or someother image receiving material.

Instead of the simple mechanical scanner diagrammatically illustrated inFig. 5, the image signal producing device may be any standard televisiontype pick-up tube, such as an image dissector, iconoscope, or imageorthicon, With a non-interlaced trace.

Having described my invention, reference should now be had fordetermining the scope thereof.

I claim:

1. In an image control cathode ray tube, an evacuated glass envelopehaving an elongated cylindrical shank closed at one end and having anenlarged portion at its other end terminating in an end face at rightangles to the longitudinal axis of said shank, an electron gun assemblywithin the closed end of said shank, a plurality of straight elongatedspaced conductors within said end face parallel to said longitudinalaxis and arranged in a row, a deflection yoke surrounding said shankadjacent said enlarged portion exteriorly energized electrically toproduce a continuously changing field, the electron beam from said gunassembly being deflectable from a path in alignment with saidlongitudinal axis for transversely scanning said row of conductorsthroughout its length for separate transmission through each of saidconductors to the exterior of said tube, a stationary electrode bladespaced from the face of said tube on its exterior and arranged parallelto and opposite from said row of conductors, a moving web of imagereceiving material positioned between said blade and said row ofconductors in spaced relation, and a confined smoke pigment of constantdensity between said row of conductors and said web, whereby thescanning electron beam as it passes through said conductors successivelyto said blade carries particles of said pigment to said web forimpingement thereon in a permanent manner, to thereby form a row ofpigmented elements and a plurality of :such rows upon continued movementof said Web, the quantity of particles deposited in a row upon said webcorresponding proportionately to the quantity of electrons passedthrough a particular conductor controlled by the instantaneous imagesignal applied to said electron gun assembly.

2. In an image control cathode ray tube, an evacuated glass envelopehaving an elongated cylindrical shank closed at one end and having anenlarged portion at its other end terminating in an end face at rightangles to the longitudinal axis of said shank, an electron gun assemblywithin the closed end of said shank, a plurality of straight elongatedspaced conductors within said end face parallel to said longitudinalaxis and arranged in a row, a deflection yoke surrounding said shankadjacent said enlarged portion exteriorly energized electrically toproduce a continuously changing field, the electron beam from said gunassembly being deflectable from a path in alignment with saidlongitudinal axis for transversely scanning said row of conductorsthroughout its length for separate transmission through each of saidconductors to the exterior of said tube, a stationary electrode bladespaced from the face of said tube on its exterior and arranged parallelto and opposite from said row of conductors, a continuously rotatingdrum with its axis parallel to said row of conductors, said electrodebeing on the interior of said drum, a web of image receiving material onthe outside of said drum and movable therewith positioned between saidblade and said conductors in spaced relation, and'a confined smokepigmentof con stant density between said row, of conductors and saidweb, whereby the scanning, electron beam as. it passes through saidconductors successively to saidblade carries particles of said pigmentto said webfor impingement thereon in a permanent manner, to therebyform a row of pigmented elements and a plurality of suchrows uponcontinued movement of said web.

3. In' an image control cathode ray tube, an evacuated g ass envelopehaving an elongated cylindrical shank closed at one end and having anenlarged portion at its other end terminating in an end face at rightangles to the longitudinal axis of said shank, an electron gun assemblywithin the closed end of said shank, a plurality of straight elongatedspaced conductors within said end face parallel to said longitudinalaxis and arranged in a row, a deflection yoke surrounding said shankadjacent said enlarged portion exteriorly energized electrically toproduce a continuously changing field, the electron beam from said gunassembly being deflectable from a path in alignment with saidlongitudinal axis for transversely scanning said row of conductorsthroughout its length for separate transmission through each of saidconduc tors to the exterior of said tube, a stationary electrode bladespaced from the face of said tube on its exterior and arranged parallelto and opposite from said row of conductors, a continuously rotatingdrum with its axis parallel to said row of conductors, said electrodebeing on the interior of said drum, a web of image receiving material onthe outside of said drum and movable therewith positioned between saidblade and said conductors in spaced relation, a confined smoke pigmentof constant density between said row of conductors and said web, wherebythe scanning electron beam as it passes through said conductorssuccessively to said blade carries particles of said pigment to said Webfor impingement thereon in a permanent manner, a formed housing adjacentsaid web and end face of said tube for delivering a moving smoke pigmentof constant density between said row of conductors and said web, and ablower in said housing for circulating said smoke pigment.

4. A method of printing comprising movably positioning an imagereceiving web With a high voltage electrode spaced from one sidethereof, arranging an image signal receiving cathode ray tube upon theother side of said web with its end face spaced therefrom, passing aconfined pigment in smoke form of constant density between said Web andend face, focusing the electron rays from said tube to pass to said endface in a line lying in a plane extending through the longitudinal axisof said tube, successively deflecting the image signal controlledelectron rays in a direction parallel to said web, conducting said raysthrough said end face, through said smoke to said electrode wherebyparticles of said pigment are impinged in spaced relation in acorresponding line upon said Web in a permanent manner.

5. In a printing device adapted for use with a cathode ray tubeconstructed for transmitting electron beams beyond its end face; astationary electrode blade spaced from the face of said tube and adaptedto receive said electron beam, a movable Web of image receiving materialinterposed in spaced relation between said blade and said tube end face,and a confined smoke pigment of constant density between said end faceand web, whereby said electrom beam scanning said end face and inpassing to said conductor carries particles of said pigment to said webfor impingement thereon in a permanent manner to thereby form a row ofpigmented elements and a plurality of such rows upon longitudinalmovement of said Web past said conductor.

6. The printing device of claim 5, and a continuously rotating drum withits axis lying in the plane of said electrode, and with said electrodearranged upon the interior of said drum, said web being movably mounted1 7 upon the outside of said drum, spaced from said endface and incontact with said smoke pigment.

' 7. The printing device of claim 5, a continuously rotating drum withits axis lying in the plane of said electrode, and with said electrodearranged upon the interior of said drum, said web being movably mountedupon the outside of said drum, spaced from said end face and in contactwith'said smoke pigment, a formed housing adjacent said web and end facefor delivering said smoke pigment between said end faceand web, and ablower in said housing for circulating said smoke pigment.

, References Cited in the file of thispatent UNITED STATES PATENTSSelenyi Aug. 11, 1931 Sabbah et a1 Sept. 24, 1935 Finch Oct. 26, 1937Bruce May 12, 1942 Kernkamp July 28, 1942 Salz June 21, 1949

